At present, in both gasoline engines and diesel engines, the actual thermal efficiency is much lower than the theoretically possible thermal efficiency. One of the primary causes for this phenomenon is that the components directly contacting high-temperature gas, such as cylinder liners, pistons, etc., are made of metal material with poor thermal insulation performance. The continuous and reliable work of metal material depends on the cooling system continuously cooling the heat absorbed from the airtight combustor. Ceramic material is a material with good thermal insulation performance. The components directly contacting high-temperature gas, such as cylinder liners, pistons, etc., are made of ceramic material, which can improve the actual thermal efficiency. However, the low reliability due to the brittleness of ceramic material becomes a technical obstacle to apply the ceramic material to the engine.
The patent (application No. CN 201410653964.6) filed by the present inventors has solved the above problems to a certain extent, but the processing and manufacturing method is complicated, the friction surfaces of the relative motion wear heavily, and some detail problems remain to be solved.